snail mail

noun phrase

Mail sent through regular postal service: Acrobat has the potential to pay for itself rather quickly by eliminating the need to send documents by courier or even regular mail(snail mail, as it is charmingly called by computer aficionados)

[1980s+ Computer; referring to the slowness of the snail]

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.Copyright (C) 2007 by HarperCollins Publishers.Cite This Source

Idioms and Phrases with snail mail

snail mail

Ordinary postal service, as opposed to electronic communications. For example, He hasn't taken to his computer so he's still using snail mail. This slangy idiom, alluding to the alleged slowness of the snail, caught on at least partly for its rhyme.
[ 1980s
]